Software for extracting data from a graph without having to click on every single point?

Here is a very good online tool: http://arohatgi.info/WebPlotDigitizer/app/


A colleague suggested I use GraphClick, a Mac OS software that includes (according to its website):

  • Automatic detection of curves (solid, dotted or dashed), symbols, bar charts, or perimeters of areas
  • Frame-by-frame digitization of QuickTime movies

The later is something I had not thought about, but might actually be useful for some teaching needs (analysis of motion from a video). My first experiences are good: the software is easy to use, includes a nice magnification UI, and automatic curve detection works fine if the graph is “clean”.


And here's a list of other possible software from this answer on Cross Validated (link thanks to @AndyW and @Paresh):

  • Engauge Digitizer (free software, GPL license) auto point / line recognition. Available in Ubuntu repository (engauge-digitizer)
  • Get Data (shareware, free trial version, $30 for personal license) has zoom window, auto point / line recognition
  • DigitizeIt (shareware, free trial version, $49 for personal license) auto point / line recognition

I used DataThief years ago. From what I remember, it is not fully automated. You start by loading a digital image and identifying the axes, some tick marks, the axis limits and the scale (i.e., linear/log/polar). This lets it handle bad scans (e.g., rotation and warping). Once it knows the bounding box of the plot, you then tell it what to extract (curves, points, errorbars, etc.).

It is written in JAVA so should run on most OS's. I believe it is free as in beer (and it might be open source).